An electrically-rewritable variable-resistive element such as ReRAM or PRAM recently draws attention. The variable resistive element is provided in a memory cell. The variable resistive element is configured to be able to reversibly change its resistance according to the supplied current. The memory cell stores data according to the change of the resistance of the variable resistive element. Therefore, it is necessary to flow a current only through the variable resistive element in the selected memory cell and not to flow a current through the variable resistive element in the non-selected memory cell. Thus, the variable resistive element is connected in series with a rectifying device such as diode.
Here, because of the request for high densification of the memory cells, the rectifying device size needs to be limited. Additionally, the electrical characteristics of the rectifying device need to be adjusted to allow repeated set operations and reset operations on a memory cell. Unfortunately, it is difficult to provide a smaller rectifying device as well as to adjust its electrical characteristics to any value.